| 摘要 |
771,576. Filtering gases. DRAGER, O. H. Nov. 30, 1954 No. 34696/54 Class 8(2) In an air filtering device consisting of a first chamber containing granular filter material 2 and of at least one second fresh-air chamber at the bottom of said first chamber, the walls of the fresh-air chamber comprising screens 6, 9 which block the filter material but permit the passage of filtered air, the fresh-air chamber consists of a casing of said screens which is mounted on the bottom of said first chamber, the screens are positioned with apertures therebetween, a pipe 4 for drawing off the filtered air is connected to the casing, the screen slot edges are so disposed that the angle of inclination to the horizontal of any imaginary line 7, 7<SP>1</SP> connecting the edges is less than the angle of repose fo the filter material and at least some of the screen edges are of angled cross section. In some embrodiments a plurality of screens are employed each of which is formed as in Fig.5 by horizontal elements the ends thereof being connected to a collecting pipe. 38. The connecting fine between the lower edge of one element, e.g. element 41a, and the top edge of the next element 41b has an inclination less than the angle of repose of the filter material HO so that apertures 39 located in the pipe 38 below the saddle of the elements are clear of filter material. The.filter screen in Fig. 17 is formed from annular dome-shaped elements 71 having distance peices 72 to provide channels 73 and having apertures 75 through which air flows in the direction of a flow 76 to the pipe 78. |
